This invention relates to a speech synthesizer capable of varying the speed of speech consisting of synthesized sounds.
An old-fashioned way of varying the speed of speech is to modify the sampling frequency, a basis for operation, while giving output sounds the impression of high speed. Such a method, however, results in varying tone and therefore it is difficult to determine that the same speaker is delivering his message more quickly. This is because the pitch interval of the speaker assumes a high rate per se and makes the sound high-pitched or shrill.